Can no longer duplicate display to external monitor on Windows 7

We have a large TV at work - I connect my laptop to it to share my screen during meetings. Until today, my laptop display has been duplicating to the TV automatically when I connect the TV cable to the laptop. The display resolution would decrease automatically to be compatible with the TV.

Today, however, it's stopped working. When I connect the cable to the TV, the display extends rather than duplicating. Using the Win+P key combination (or Fn+F7 on my Lenovo laptop), I can choose to duplicate the display - but when I do this, it ends up only displaying on the laptop. I can get it to display on the TV by hitting Win+P and choosing "projector only", but then I can't see what I'm doing on the laptop screen.

I have a Lenovo W520 laptop running Windows 7, connected to the TV using a DisplayPort-to-HDMI converter cable. The TV's native resolution is 1280x720; the laptop's native resolution is 1600x900.

I've tried booting with the TV cable already connected; I've tried manually lowering the display resolution on the laptop to 1280x720 before duplicating the display. Neither works.

Does anyone have any other suggestions?

Solution 1:

You should have an icon in the lower right of your screen (taskbar) related to your graphics in your computer (Nvidia, Intel, etc.). Right-clicking that icon you should be able to get to something like "display settings", where you should find an option for cloning your display, or dual-display, or something like that. Using that option should restore the dual-monitor display function.

If that doesn't take care of it, it would be much more helpful to have your laptop's specs and configuration. Graphics card, info, etc.

Solution 2:

I had the same issue on Vista. I have a 50" HDTV at home that I watch Netflix from my laptop. Every few days I would take the laptop to work and when I would get home connect the HDMI cable and the screen was cloned onto the 50" HDTV.

In my taskbar I found "Intel(R) Graphics Media Accelerator Driver for Mobile".

1. then I right clicked choose "Graphic Options"
2. moused over "Output to"
3. moused over "Clone Displays"
4. clicked on "Built-in Display + Digital Television" and resolved my issue.

Solution 3:

I had a similar problem with my laptop going into my Sony LED TV. Turned out to be a setting on my TV remote control. It was on THEATER mode, once I clicked to switch it off, no problem.